Bitcoin transactions cannot be reversed if the receiving party doesn't agree to the refund. ABC noted:

The bitcoin transaction trail is designed to be anonymous, which has led to speculation this was an inside job and that TradeFortress took the coins for himself.

But when asked by the ABC's AM he strenuously denied those accusations, and said that despite his $1 million loss he is unlikely to report the theft to the police.

"The police don't have access to any more information than any user does when it comes to bitcoin. Some say it gives them control of their money," TradeFortress said.

The Sydney Morning Herald reports that Tradefortress operated out of computers located in this apartment building in Hornsby, New South Wales:

Google Street View

It is possible to steal Bitcoin — an online currency that uses an uncrackable cryptography to make itself permanent — but it is difficult to hide the money afterward. Wired notes:

Bitcoin trades are public: all transactions are shared in a publicly available file called the Blockchain that’s posted to the Bitcoin peer-to-peer network.

That public ledger makes it pretty tough for big-time criminals to launder money through the network. At least that’s what researchers at the University of California and George Mason University found when they studied the Bitcoin network by developing sophisticated tools to track how money was moving around it.

Meiklejohn and her fellow researchers tried some of those services out — sites with names like Bitcoin Laundry and Bitmix — and they report some pretty rough experiences. One service didn’t work. It simply returned the same Bitcoins, un-laundered.